[lpd154]

Hey guys I need some help! In the past month I have replaced my stock injectors with a set of stage 1 injectors and I've put in a new HPOP. When I first replaced the injectors the truck ran smooth but it was extremely weak, after running a test on the HPOP we decided that the HPOP was weak so we replaced it. Now the truck is running stronger but it is still not up to the performance level it was running at with just the DP tuner and the stock injectors and old pump. I have been in contact with Jody and we are trying to get to the bottom of it but I figured it couldn't hurt to see if anyone else out there had experienced this.

It seems that the ICP pressure is still on the low side especially in the lower end of the RPM range. I have a video of a data log if anyone would like for me to email it to them to look over. Can't figure out how to upload it to the post.

 

[mustangii]

maybe your tuner needs recalibrated to match the new injectors.

 

[RT]

maybe your tuner needs recalibrated to match the new injectors.

Boy, I bet Jody wishes he had thought of that. :worried:

 

[TonkaThunder]

Im interested to see what u find out becuse I am in the market for new injectors and I am not putting stock sticks back in, but I dont feel like putting in a new HPOP. But Jody will take good care of u.

 

[RT]

I just had a thought (shocking, I know) - I bet your fuel pressure is low. It isn't a measured parameter, so the PCM wouldn't catch it. The Stage 1's are more dependent upon adequate fuel pressure. There are several places where the problem could be, from tank obstructions, pump problems, filter issues, and the most likely - fuel pressure regulator. You might pull your FPR off (on the side of the fuel filter assembly) and make sure it isn't gunked up. If you can, put a fuel pressure gauge on it.

 

[lpd154]

Jody adjusted my tunes to compensate for the new injectors, not that I'm not sure the problem isn't still in that area though.

 

[lpd154]

I just had a thought (shocking, I know) - I bet your fuel pressure is low. It isn't a measured parameter, so the PCM wouldn't catch it. The Stage 1's are more dependent upon adequate fuel pressure. There are several places where the problem could be, from tank obstructions, pump problems, filter issues, and the most likely - fuel pressure regulator. You might pull your FPR off (on the side of the fuel filter assembly) and make sure it isn't gunked up. If you can, put a fuel pressure gauge on it.

I thought that at first but when me and my mechanic both took some time to think about issue We both felt i would be having a bigger drop off in the performance as the performance level of the tunes in increased, but the really strange thing is that my stock and 60 econo tunes seem to be almost identical at least as far as how the truck feels performance wise, both tunes feel weak on the low end of the throttle. However if I switch to the 100hp performance tunes the truck is off the charts power and performance wise.

Is there something I missing in my thoughts about this, I'm still very new to the upgrade market and I'm nit very skilled on the inner workings of tuning and fuel delivery.

 

[klhansen]

What were you logging on your data log? You should be looking at ICP and IPR duty cycle at a minimum.

If you're using AutoEnginuity, you can export the data log run to a CSV file which can then be imported into Excel and a graph developed. That's the easiest way to see what's going on as opposed to looking at a bunch of numbers changing on the screen. Or you could just post the CSV file of the run.

I agree with RT, that your problem may be fuel pressure related. Getting a pressure gauge on it is the first step to checking that out.

Have you tried running it with the ICP sensor unplugged? Maybe the sensor is going bad and not getting the correct signal to the PCM. Also check the coil on the IPR to be sure that it's snugged in place and can't move around on the stem of the IPR.

You should also unload the program to see if it does the same thing in stock setting, although if your injectors are single shots, that may not work well.